I see them spec'd identical, the carbon frame is $5100.00 the aluminum is $4400.00?
That said, I ride a carbon hardtail and an aluminum Epic. Carbon frames give the same advantages on a trail bike that they do on a road bike. Stiffer and better ride qualities than aluminum. The jury is still trying to decide the durability issue. On a full squishy you probably don't notice the ride as much as a hardtail.

PS. Profail, The Epic is only more inactive if the owner sets it up that way.